Overhead video system for an aircraft

ABSTRACT

An overhead video system for an aircraft is disclosed. The overhead video system comprises a wireless overhead video unit; and at least one mounting rail detachably coupled to the wireless overhead video unit. The mounting rail provides structural support and electrical power to the wireless overhead video unit. A system in one embodiment may use mounting rails that double as power rails supplying power to the wireless overhead video unit. Video control and content streaming is accomplished over a wireless link. The power rail control may be accomplished remotely via a standard or solid state relay. Normal rail power for the rail mounted video system may come from the utility bus.

FIELD OF THE INVENTION

The present invention relates generally to an aircraft and more specifically to an overhead video system in the aircraft.

BACKGROUND OF THE INVENTION

In today's commercial airplanes, the passenger overhead video unit has complex power, video and discrete wiring, and is difficult to install. When a passenger service unit needs to be moved or replaced, it can take several minutes to accomplish the job based upon the complexity of the system. When this move or replace is associated with a seat repitch or retrofit within the aircraft, a great deal of time can be lost. Accordingly, it is desired to provide for the installation and removal of overhead video passenger service units without the difficulties and time loss associated with the conventional overhead video passenger service.

Accordingly, what is needed is a system and method for providing a simple, lightweight and reliable overhead video system in an aircraft. The present invention addresses such a need.

SUMMARY OF THE INVENTION

An overhead video system for an aircraft is disclosed. The overhead video system comprises a wireless overhead video unit; and at least one mounting rail detachably coupled to the wireless overhead video unit. The mounting rail provides structural support and electrical power to the wireless overhead video unit.

A system in one embodiment may use mounting rails that double as power rails supplying power to the wireless overhead video unit. Video control and content streaming is accomplished over a wireless link. The power rail control may be accomplished remotely via a standard or solid state relay. Normal rail power for the rail mounted video system may come from the utility bus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic diagram of a cabin services system in accordance with a number of embodiments.

FIG. 2A illustrates a block diagram of a cabin services system in accordance with one of the embodiments.

FIG. 2B illustrates a block diagram of an alternate embodiment of a cabin services system in accordance with one of the embodiments.

FIG. 2C illustrates one implementation of the cabin attendant panel.

FIG. 3 is a diagram that illustrates the operation of passenger service unit mounting rails with circuits connected thereto.

FIG. 4 is an example of a simplified wireless overhead electronics unit.

FIG. 5 is a perspective view of a portion of a passenger service unit module.

FIGS. 6A and 6B are top and front views of the embodiment of a wireless overhead video unit.

FIG. 7 is a block diagram of one embodiment of an overhead video system.

FIG. 8 is a block diagram of the embodiment of a power switching system for use with a wireless overhead video unit.

DETAILED DESCRIPTION

The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiments and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein.

A method and system in accordance with a number of embodiments streamlines the process for installation and removal of a wireless overhead video unit over conventional overhead video passenger service units. These embodiments may be utilized in conjunction with a rail system within an aircraft for providing power to a wireless overhead video unit. In so doing, a system is provided that may allow for a wireless overhead video unit to be easily installed and removed.

U.S. patent application Ser. No. 11/303,498 entitled “Simplified Power System for a Cabin Services System for an Aircraft”, filed on Dec. 16, 2005 and assigned to the assignee of the present application, describes a powered rail system in accordance with a number of embodiments and is incorporated by reference in its entirety herein. The embodiment of the wireless overhead video unit is described in the context of a cabin services unit; however, one of ordinary skill in the art readily recognizes a variety of cabin services units could be utilized with a wireless overhead video unit and they would be within the spirit and scope of the present invention. Therefore the following description is utilized to describe with particularity the features of the described embodiment, but is in no way limited by the embodiments.

A cabin services system 100 according to a number of embodiments is illustrated in FIG. 1. The cabin services system 100 may include a plurality of wireless networks 102. Each of the wireless networks 102 may transmit and receive passenger services commands. Each of the wireless networks 102 may be preferably associated with a seat group. The cabin services system 100 may further include wireless passenger control units 202 a-202 n, passenger service units 204 a-204 n, a plurality of cabin zone units 114, a cabin control unit (not shown) and a cabin attendant panel 112. Each passenger control unit 202 a-202 n may transmit cabin services system commands to a corresponding passenger service unit 204 a-204 n. Each passenger service unit 204 a-204 n may include a wireless receiver (not shown) and a controller (not shown) which are used to control passenger service unit functionality. The cabin services system 100 may further include a passenger service unit power rail (not shown) which is integrated with a passenger service unit mounting rail (not shown) to provide electrical power to each passenger service unit 204 a-204 n. Finally, individual personal air outlet fans may be installed in each passenger service unit 204 a-204 n to eliminate flex hose hookups that are typically required in conventional cabin services systems.

Additionally, systems may be greatly simplified, passenger controls may be more easily reached by passengers, and each passenger service unit 204 a-204 n may be quickly installed and maintained without any wiring or duct hookups.

Similarly, wireless interfaces may be used to provide data or control of other passenger service unit module functions. For example, video monitors mounted onto a passenger service unit may receive video data wirelessly via a cabin wireless network. Also, passenger signage can be controlled (turned on/off or fed content for display) via a wireless interface.

Taken together, these wireless interfaces allow for the elimination of wiring to passenger service unit modules. This leaves electrical power as the electrical interface to each passenger service unit module via the passenger service unit mounting rails themselves and also provides a means for powering non-essential or essential loads on these rails. In one implementation, the passenger service unit mounting rails are energized with electricity such that when a passenger service unit module is clipped to the mounting rail, electrical contact is also made between the passenger service unit module and the mounting rail to provide electrical energy to the passenger service unit module.

The powered passenger service unit rail system is comprised of the following components:

Airplane Wiring

Airplane wiring may consist of four wires:

-   -   Two non-essential power wires (typically 115 VAC and current         return)     -   Two essential power wires (typically 28 VDC and current return)         Stow Bin Assembly

A typical commercial stow bin assembly consists of a housing assembly that supports a stow bin, passenger service unit mounting rails and other equipment.

Simplified Overhead Electronics Unit (SOEU)

The simplified overhead electronics unit (SOEU) for the embodiment performs three functions:

-   -   Convert power inputs into a “safe-to-touch” power output (such         as 12V DC)     -   Switch the outputs from being powered by the non-essential power         input to being powered by the essential power input whenever the         essential bus becomes live     -   Reversing the polarity of the outputs when the essential bus         becomes live

Note that the simplified overhead electronics unit must perform its functions while maintaining circuit separation between the non-essential and the essential busses at all times.

To describe the features of the present embodiment in more detail refer now to the following description in conjunction with the accompanying figures.

Cabin Services System (CSS)

In one embodiment, a cabin services system 100′ may include a cabin control unit 113 wired to a cabin attendant panel 112′ as shown in FIG. 2A. The cabin control unit 113 may be wired to a plurality of cabin zone units 114. The cabin zone units 113 may in turn communicate wirelessly to a plurality of wireless seat group networks 115. Each wireless seat group network 200 may include a plurality of passenger control units 202 a-202 n that communicate wirelessly with one passenger service unit 204. In this method, data from the cabin attendant panel 112′ may be relayed by wiring to the cabin zone unit 114′ data and may be transmitted by the cabin zone unit 114′ wirelessly to the passenger service unit 204. The wiring from the cabin attendant panel 112′ to cabin zone unit 114′ may exist for functions other than passenger service functions, (such as general cabin lighting control, cabin air temperature data, zonal attendant call light control and many other functions not related to the passenger service functions) thereby eliminating the need to add extra wire or wireless radio hardware for the cabin attendant panel 112′ to passenger service unit 204′ communication.

FIG. 2B illustrates a block diagram of an alternate embodiment of a cabin services system 100″. The cabin services system 100″ may include a wireless cabin attendant panel 112″ that may communicate wirelessly with a plurality of wireless seat group networks. A wireless seat group network 200 may include a plurality of passenger control units 202′a-202′n that may communicate wirelessly with a passenger service unit 204′. This method may allow small commercial aircraft to perform cabin services functions normally found on large commercial aircraft. Further, the wireless cabin attendant panel 112″ may wirelessly transmit commands to a plurality of other airplane components in order to control functions such as general cabin lighting, zonal attendant call light, and record cabin air temperature data. Each of the components listed above may be wirelessly enabled to afford this functionality.

Passenger Service Unit (PSU) 204

The passenger service unit 204 may comprise a wireless receiver 206, a controller 208, memory 210, reading lights 212 a-212 n, a flight attendant call light 214, a flight attendant call cancellation switch 216, personal air outlets 218 a-218 n, and a reed switch 220. The features of each of these components are described in more detail in conjunction with the accompanying figures hereunder.

The wireless passenger control unit transmitter 202 may allow for communication with the passenger service unit 204 without an in-flight entertainment system or any other wires. Thus, the cabin services system is not reliant on an in-flight entertainment system and an aircraft can be built without a conventional in-flight entertainment system. This allows airlines to choose not to install wired in-flight entertainment systems (which significantly reduces weight) or to use the latest portable in-flight entertainment systems, such as the digEplayer or eXpress, on widebody aircraft.

A passenger control unit including the wireless passenger control unit transmitter 202 may be installed anywhere in the passenger seat (seat arm, seat back, etc.) within easy reach of the passenger. Wireless passenger control unit transmitters 202 may be battery powered, or may use energy harvesting for power without batteries. An energy harvesting wireless passenger control unit transmitter may be constructed, for example, by integrating an EnOcean piezoelectric or electrodynamic wireless transmitter (www.enocean.com, part numbers PTM100 or PTM200) into a passenger control unit such that passenger actuation of the passenger control unit control buttons closes a specific control switch on the EnOcean transmitter and depresses the energy bar, thus resulting in wireless transmission of command telegrams from the passenger control unit to a receiver (for example, an EnOcean receiver—EnOcean P/N RCM 120) mounted in the passenger service unit. The command telegrams may include an identifier unique to the transmitter and indication of which control switch was closed at the time of pressing the energy bar.

Passenger Service Unit (PSU) Functionality

Passenger service unit modules may come in many forms. Any given passenger service unit module may include one or more of the following functionalities:

-   -   Flight attendant call light     -   Reading light     -   Personal air outlets     -   Emergency oxygen     -   In-flight entertainment system control such as video or audio         channel selection     -   Cabin signage such as “fasten seat belt”, “no smoking” or other         passenger information

It should be understood by one of ordinary skill in the art that a variety of other functions could be included and their use would be within the spirit and scope of the present embodiment.

In one embodiment, each passenger service unit may utilize the following features to allow it to easily snap onto a mounting rail in an aircraft without wire, duct or tube hookups: a 12V DC powered mounting rail, wireless technology, and fans mounted onto a passenger service unit.

Powered mounting rail: the passenger service unit mounting rail provides both a structural interface for installing a passenger service unit as well as an electrical power interface. Each passenger service unit may simply snap onto the mounting rail for both mechanical attachment and for electrical power.

Wireless technology: together, the wireless passenger control unit, wireless interface to the cabin attendant panel and the passenger service unit power rail (or power line) within the mounting rail may eliminate the need to hook up wires to a passenger service unit.

Fans mounted onto a passenger service unit: ducting for a personal air outlet and hookup to each passenger service unit may be replaced by individual personal air outlet fans built into each passenger service unit. This results in less noise (compared to high pressure ducting and nozzles of a conventional personal air outlet).

The reading light, flight attendant cal, nozzles and fans of a personal air outlet and emergency oxygen may be assembled in an integrated passenger service unit module that snaps onto the mounting rail without any wire or duct hookups.

In one implementation, fans (mounted onto a passenger service unit) may draw “fresh” air into a passenger service unit plenum through an inlet grill located adjacent to the cabin air distribution nozzles. In such an implementation, ducts of a personal air outlet may be eliminated and cabin noise may be reduced.

In one implementation, oxygen masks may be deployed by turning off power to a utility bus on the passenger service unit mounting rail and momentarily turning on an essential power bus and reversing electrical polarity on a power rail within the passenger service unit mounting rail. Current will then flow through a diode in the oxygen circuit to activate the mask drop solenoid.

Cabin Attendant Panel (CAP)

FIG. 2C illustrates one implementation of the cabin attendant panel 112. The wireless cabin attendant panel 112 may be used to transmit wireless control signals via control button 402 directly to groups of passenger service units for functions such as turning on/off passenger signage (e.g., “No Smoking”, “Fasten Seat Belt”, etc.), and for resetting the passenger service units via reset button 404 during gate turnaround between flights (e.g., turning off all reading lights, personal air outlets, and flight attendant call lights; and turning on all “No Smoking” and “Fasten Seat Belt” signs). In this manner, the cabin control unit and cabin zone module may be bypassed, greatly simplifying the system architecture.

In a preferred implementation of the cabin attendant panel, the cabin attendant panel may make use of other aircraft wireless transmitters located in various positions in the airplane to relay its control signals to the seat group networks. These other wireless transmitters can include a wireless function added to the cabin zone modules (part of the cabin services system). In this case, the cabin attendant panel may be part of a wired or wireless network common to these zone control electronic boxes. It may also be part of other aircraft systems, such as a wireless cabin network. The cabin attendant panel can further include a display (not shown) for displaying data (e.g., prognostic data) to a mechanic or flight personnel, as described in greater detail below.

Passenger Service Unit (PSU) Mounting Rails

FIG. 3 is a diagram that illustrates the operation of the passenger service unit mounting rails with passenger service unit circuits as indicated by loads 403 a, 403 b and 403 c connected thereto. As is seen, under normal operating conditions, a diode 402 in series with each passenger service unit module circuit allows current to flow through non-essential circuits 408. Non-essential circuits are, for example, circuits for in-flight entertainment monitors, reading lights and flight attendant call lights. For essential circuits 410, such as one for oxygen deployment, a diode 404 in series prevents current from flowing into the circuit. Thus, under non-normal operating conditions, such as during emergency oxygen deployment, the output of the wireless? overhead electronics unit 406 reverts from a non-essential power mode to an essential power mode and the output polarity is reversed. Thus, the diodes 402 on the non-essential circuits prevent current to flow through them while the diodes 404 on the essential circuits now allow current to flow through them. This can be used, for example, to momentarily power a solenoid that opens an oxygen mask door thus allowing oxygen masks to fall into the cabin, or, for example, to continuously power a wirelessly activated oxygen system.

Note that if a circuit 412 requires power during both normal and non-normal conditions, diodes may be used to provide power to the circuit 412 under either condition. Also note that if the circuit 412 could operate with either polarity, no diodes would be necessary and the circuit may be connected to each of the rails.

In one implementation, the 12V DC mounting rail contact and the current return contact may be widely spaced. In this implementation, such a design helps to prevent accidental shorting across the contacts with, e.g., a conductive tool that might otherwise startle a mechanic by discharging sparks. Additionally, all portions of the passenger service unit mounting rails that cannot be contacted by the electrical contact of the passenger service unit may be made from non-conductive materials or finished with non-conductive finishes as another preventive measure against accidental shorting.

The passenger service unit power rail may implement any low voltage power type, AC or DC. Many power rail designs other than that shown in FIG. 3 are feasible. For example, the male spring contact may be moved to the passenger service unit with the female contact inserted into a groove in the mounting rail arm. In this case, both the 12V DC and return rails may be located on the same side of the passenger service unit (instead of opposite sides) since both mounting rail contacts can be recessed protecting them from accidental shorting with, e.g., a conductive tool.

FIG. 4 is an embodiment of a simplified overhead electronics unit (SOEU) 400. As is seen, a power panel 402 provides power to the simplified overhead electronics unit 406 via a non-essential power bus 404 and/or an essential power bus 406. In this embodiment the non-essential power bus 404 may be 115 VAC and the essential power bus 406 may be 28 VDC. The simplified overhead electronics unit 400 may include a first converter 408 for converting the essential voltage from in this embodiment 28 VDC to 12 VDC and a second converter 410 for converting the essential voltage bus from 115 VAC to 12 VDC. The simplified overhead electronics unit 406 may be typically mounted on the stow bin assembly. In this example, only power from the non-essential power bus inputs are being used to create the 12 VDC output under normal operating conditions (when the essential bus 406 is not live). When the essential power bus 406 becomes live, a relay may be energized to switch the output from being driven by the non-essential power bus 404 to being driven by the essential power bus 406 input. Note that the output polarity will be reversed relative to the normal operating condition when this occurs.

In this example:

-   -   The non-essential power bus 404 may be 115 VAC and may be         transformed to 12 VDC by an AC-to-DC converter 610 within the         simplified overhead electronics unit 400.     -   The non-essential power bus 404 may also be turned off without         turning on the essential power bus 406 by opening a circuit         breaker or relay, typically located in a power panel.     -   The essential power bus 406 may be 28 VDC and may be converted         to 12 VDC by a DC-to-DC converter 608 within the simplified         overhead electronics unit 400.

The essential power bus 406 may typically be turned on via a relay typically located in a power panel. The relay may, for example, be activated by a switch 412 in the Flight Deck, such as for emergency oxygen deployment.

-   -   The power buses may be fed through the simplified overhead         electronics unit 406 for installation convenience. This may         allow several simplified overhead electronic units 400 to be         daisy chained together down the airplane.

There are several ways to accomplish the simplified overhead electronics unit 400 functionality. The example circuit shown in FIG. 4 is just one way to implement this function.

Passenger Service Unit Mounting Rail

FIG. 5 is a perspective view of a portion of the passenger service unit module 300. The portion of the passenger service unit module 300 illustrated in FIG. 5 shows an electrical contact assembly 301. The assembly 301 may comprise an electrical spring contact 302 and a plastic, non-conductive, insulating support 304. The electrical spring contact 302 may be made of, for example, beryllium copper that is nickel and gold plated. The electrical spring contact 302 may be designed to clip onto the round portion of electrically conductive passenger service unit mounting rail 306. The plastic support 304 may be also designed to clip onto the passenger service unit mounting rail 306 and may be intended to support the electrical spring contact 302 and to prevent the electrical spring contact 302 from rocking back and forth on the passenger service unit mounting rail 306. The electrical contact assembly 301 may be loosely fastened to a passenger service unit module such that when a passenger service unit module vibrates under the passenger service unit mounting rail 306, the electrical spring contact 302 will float over the passenger service unit module and maintain its grip on the passenger service unit mounting rail 306. With these elements in place, the electrical spring contact 302 may mate with the electrically conductive portion of the passenger service unit mounting rail 306 when the passenger service unit is installed and held in place by the passenger service unit catches (not shown).

Accordingly, each passenger service unit module 300 may receive electrical power from the mounting rail 306 via its electrical spring contacts 302.

Passenger service unit mounting rails may be typically constructed from an aluminum extrusion that is approximately the same length as the stow bin assembly. In this embodiment the mounting rails may have the following features:

-   -   Each rail may be electrically connected to one of the outputs         from the simplified overhead electronics unit 406 via a wire.         Thus, one rail may be connected to the normally positive DC         output and the other rail may be connected to the normally         negative DC output.     -   The edge of the rail that passenger service unit module clips         may attach to is kept electrically conductive. While most         surfaces of the rail are typically primed and painted, the         aluminum rail along this edge may be plated, for example, with         nickel and gold to provide electrical conduction.

Note that the simplified overhead electronics unit above may energize these rails with 12 VDC voltage.

In a system and method in accordance with the present embodiment the passenger service unit mounting rails may perform two functions:

(1) Mechanical support of the passenger service unit modules; and

(2) Electrical supply to the passenger service unit modules.

This may minimize the addition of new components or weight to the airplane. However, because of this dual functionality, electrical isolation may be required between the rail and any adjacent conductive airplane parts. Thus, plastic bushings may likely be used at the rail mounting points.

When combined with a wireless data infrastructure, the mounting rails may greatly simplifies the passenger service unit installation by providing electrical power to passenger service unit modules via the passenger service unit mounting rails instead of through electrical wiring. With no data or power wiring interfaces, passenger service unit modules may be able to be installed, removed or relocated much more rapidly.

Wireless Overhead Video System

FIGS. 6 a and 6 b are top and side views of the embodiment of a wireless overhead video unit 600 in accordance with several embodiments. The wireless overhead video unit 600 may, for example, be part of an in flight entertainment system which may be controlled by the passenger service unit 204. The wireless overhead video unit 600 may be detachably mounted on the passenger service mounting rails 306 a and 306 b. As is seen, the wireless overhead video unit 600 may be removed or attached to the rails 306 by quick connect interface that provides a connection to the power, typically 12V DC.

FIG. 7 is a block diagram of one embodiment of an overhead video system 700. The wireless system 700 may comprise a wireless notebook PC with an LCD display 702 to provide the wireless overhead video unit 700 and a latching mechanism 750. The latching mechanism 750 may include a hinge 756, latch pin 758, 12 VDC solenoid 760 and a monitor activation arm 762. As before mentioned the rails 306 a and 306 b shown in FIGS. 6 a and 6 b may provide a quick connect interface and may provide the structural interconnect and 12 VDC power.

In one embodiment, deployment of the wireless overhead video unit 700 may be controlled wirelessly through a discrete signal from the integrated notebook or tablet PC. The display screen 704 may be powered by 12 VDC from the powered rails 306. Screen drop actuation control may be provided via discrete signal outputs from the wireless overhead video unit 700 controlling the LCD screen 704 and allowing the screen to drop from the surfaces 712 a and 712 b. The discrete output may be commanded via a wireless link. Content may be streamed to the display screen 202 via a wireless link. When a motor (not shown) is energized, the display screen 704 may be deployed.

The system 700 may be completely self-contained. The retractable or fixed display monitor 762 may be integrated into the base where the power supply is located.

Audio distribution to each passenger may be accomplished in several ways. One method may be to flow the audio to the passenger address system using the on-board PA speakers.

Another method may use an FM transmitter and inexpensive digital FM radio receivers. The airplane entertainment audio content from the overhead system may be transmitted to the passenger via FM wireless signals. These commercial FM radio receivers may be purchased by the passengers much like headsets are purchased in-flight now. The radio and headset may be inexpensive enough to allow the passenger to keep them when they leave the plane.

The radio may use a frequency at the low end of the commercial FM radio band (88 MHz-108 MHz). Ideally the frequency chosen may be the first one scanned by the entertainment radio set, allowing the passenger to receive the intended audio as soon as the radio is turned on.

The radio cover plate may also be branded with the airline logo, giving the airline additional advertising options. Since the passengers will take the radio with them, the only action required by the flight attendant may be to pass out the radios, collect the fees, and turn on the in-flight entertainment (IFE) system.

The radio may also be made to utilize a different frequency other than standard broadcast FM radio if desired, but the passengers would not be able to use the new radios anywhere other than the airplane.

FIG. 8 is a block diagram of the embodiment of a power switching system 800 for use with a wireless overhead video unit 704 in accordance with a number of embodiments. The power switching system 800 may utilize a relay 808 (either a mechanical or a solid state). Since the video unit 802 may share the power rails 304 a-304 b with the oxygen PSU (not shown), each PSU mounted video unit 802 may be protected by diode 812 to prevent power from being applied to the video system 802 while oxygen may be deployed.

In this system, the power rails 306 a-306 b may also double as the oxygen mask deploy wiring. The oxygen deploy discrete output 804 may be tied to the relay coil 808. When oxygen is commanded, the relay 808 may be energized and 12 VDC power from the primary bus may be routed to the power rails 306 a-306 b in reverse polarity causing the oxygen PSU door solenoid 806 to be energized causing the oxygen masks (not shown) to deploy. The diode 812 in the video PSU 802 may keep the video system off until utility bus power is restored and the oxygen discrete is returned to its normal state. The details of one embodiment of an oxygen deployment system are described, for example, in U.S. patent application Ser. No. 11/303,498 entitled “Simplified Power System for a Cabin Services System for an Aircraft”, filed on Dec. 16, 2005, assigned to the assignee of the present invention, and incorporated by reference herein.

Other Embodiments

Many other embodiments of this system are possible:

In addition, separate power rails may be added to the stowage bin assembly, parallel to the passenger service unit mounting rails, in order to provide the electrical power function.

This system does not rely on wireless data communication to the passenger service unit modules. Other communication options may include traditional wires or communications over power line (COPL) technologies.

Circuits that need to operate when power is completely shut off from the rails may include a battery or capacitor that is charged via the rails during normal operation.

The power rail may use any of low voltage power type, AC or DC. Many power rail and electrical contact designs other than that shown in FIG. 5 are feasible.

Accordingly, a system and method in accordance with the embodiment provides an overhead video system that is integrated with a passenger service unit power rail to provide a modular system. As a result, the overhead system can be installed and replaced in an efficient fashion.

Although the present embodiment has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present embodiment. For example, implementations of a cabin services system described above can be implemented in any type of commercial vehicles including, e.g., helicopters, passenger ships, automobiles, and so on. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims. 

1. An overhead video system for a vehicle, the overhead video system comprising: a mounting rail including an elongated member that extends above a plurality of seats in the vehicle, wherein the elongated member includes a cylindrical portion that is electrically conductive; multiple overhead video units configured to be detachably coupled to the mounting rail, the cylindrical portion providing structural support and electrical power to each of the overhead video units; and an electrical contact assembly coupled to each of the overhead units, the electrical contact assembly comprising an electrical spring contact and an insulating support member, wherein the electrical spring contact is clipped on the cylindrical portion of the mounting rail and the insulating support member is clipped on the cylindrical portion of the mounting rail in the same manner as the electrical spring contact to provide support for the electrical spring contact, wherein each of the overhead video units can be removed from the mounting rail by unclipping the electrical contact assembly.
 2. The overhead video system of claim 1, wherein the insulating support member clips on to a different location of the cylindrical portion of the rail that is electrically conductive, the different location being different than a location of the cylindrical portion onto which the electrical spring contact is clipped.
 3. The overhead video system of claim 1, wherein the mounting rail is one of a plurality of mounting rails to which the overhead video units are detachably coupled and providing structural support and electrical power to each of the overhead video units.
 4. The overhead video system of claim 1, wherein the electrical spring contact includes an electrical clip that clips onto a first portion of the cylindrical portion of the mounting rail and the insulating support member includes an insulating clip, distinct from the electrical clip, that clips onto a second, different portion of the cylindrical portion of the mounting rail.
 5. The overhead video system of claim 1, wherein at least one of the overhead video units displays content streamed via a wireless link.
 6. The overhead video system of claim 1 wherein the overhead video unit comprises: a personal computer including an LCD display; and a connector for detachably coupling the personal computer to the at least one mounting rail.
 7. The overhead video system of claim 6 wherein a wireless screen drop activation control is provided for the LCD display to allow for viewing of content on the display, wherein a discrete signal is provided by at least one of the overhead video units over a wireless link to the wireless screen drop activation control to allow the LCD display of the at least one overhead video unit to drop relative to a surrounding surface. 